A high-voltage system equipment unit which accommodates therein high-voltage system equipment and/or a battery unit which accommodates therein a battery is installed in a vehicle using a motor as a drive source such as an electric vehicle, a hybrid electric vehicle or the like. In vehicles of this type, in order to prevent the deterioration in performance of the high-voltage system equipment and/or the battery due to an abnormal increase in temperature, the high-voltage system equipment and/or the battery is cooled with air taken in from the passenger compartment to maintain the temperature of the high-voltage system equipment and/or the battery in a proper range.
In the vehicle described in Patent Literature 1, it is described that a discharge passage is formed by a floor board and ribs at a downstream of a battery for passage of air used to cool the battery and that the air used to cool the battery is divided to the left and right by a branch portion in the discharge passage.
In the vehicle described in Patent Literature 2, a battery unit is disposed underneath a floor below a front seat. In addition, an air introduction duct whose air inlet port is formed in a rear seat side step disposed on one side of a transverse direction of a vehicle is attached to one end portion of the battery unit in the transverse direction, and an air discharge duct whose air outlet port is formed in a rear seat side step disposed on the other side of the transverse direction is attached to the other end portion of the battery unit in the transverse direction, so that air is circulated within a passenger compartment to cool the batteries.